Traffic signal



April 10, 1928.

F. BUCHANAN TRAFFIC SIGNAL Filed Sept. 24. 1924 2 Sheets-Sheet 1 IN VENTOR.

A T TORN E Y.

.April 10, 1928.

F. BUCHANAN 2 Sheets-Sheet 2 Patented Apr. 10, 1928.

UNITED STATES FRANK BUCHANIA N, OF SYRACUSE, NEW YORK, ASSIGNOR TOCROUSE-HINDS COMPANY,

PATENT OFFICE.

OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK.

TRAFFIC SIGNAL.

Application filed September 24, 1924. Serial No. 739,744.

This invention relates to signals and particularly to traflic signals,such as are used and are coming into more extensive use to signal anddirect traffic at the street intersections of cities, and has for itsobject a traffic signal utilizing colored lights, and means by which thesi nal in which the light is on has wide visi ility and is not renderedinvis ible or ineffective or less effective by dayli ht or strongsunlight conditions, and in w iich the signals, which are intended to beoff or inactive, will not give the effect of being on or active bydaylight or bright sunlight conditions, and also by which the sunlightcannot enter the signal and give the effect of a so-called phantomsignal.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is bad to the accompanyingdrawings in which like characters designate corresponding parts in allthe views.

Figure'l is a front elevation of a'traflic signal embod ing myinvention. Figure 2 is an enlarge vertical sectional view taken on line2-2,- Figure 1.

Figure 3 is a fragmentary face view of one of the lens.

Figure 4 is an enlarged fragmentary view of the lens.

Figures 5 and 6 are enlarged sectional views taken on line 55, 66, Fig.4.

Figure 7 is a view similar to Fig. 2 of another form of my signal.

In traflic signals embodying electric lights and colored lenses as forinstance, signals which embody a red light, which when on signals thetraflic to stop, and a green light which signals go or an amber light tosignal the trafiic that the signal is to be changed from red to green orgreen to red, it is difiicult, if not impossible under. certain daylight conditions for the observer to determine which signal is operated.For instance, in bright sunlight there is oftentimes very littlecontrast between the signals in which the lamps are on and those inwhich the lamps are off for the reason that some of the sunlight ra sreflect off from the colored lenses or pass through the lenses and arere flected by the reflector back through the colored lenses, so that,the observer cannot determine whether a green or a red signal isintended to be displayed, and hence, mistakes the signal.

Also under certain conditions, as late in the afternoon, when the sun iswell down toward the horizon, the sunlight shines in through one signaland out through :1 diametrically opposite signal giving a phantomsignal, this being particularly so when one lamp is used to give lightto two 0pposite signals, that is, when one lamp supplies the light totwo red signals or two green signals or one green and one red which areopposite each other.

The object of the present invention is a signal in which the contrastbetween a signal in which the lamp is on is so great uuder most severedaylight conditions that the observer cannot mistake the signal and inwhich it is impossible or diflicult for the sunlight to pass through thelenses.

This traffic signal comprises a. casing or housing of any suitableconstruction. a light source or lamp means for projecting the light,including a lens formed to widely diffuse the light rays to preventdirect rays from passing through the lens from the outside thereof, andpreferably also including a reflector.

The casing or housing may be of any suitable form, size andconstruction, it here bein illustrated as including a box 1. The lig tsource is usually an incandescent electric lamp 2 located in thehousing, the lamp being controlled by a suitable switch. The lamp 2 islocated in juxtaposition to a concave or parabolic reflector 3 in thehousing and to a lens 4.

The lens 4 is supported by the housing and is provided with lightdiffusing means or screen means for preventing direct rays of sunlightfrom passing through the lens, and also preventing rays of light fromthe lamp or from the inside of the housing from passing straight throughthe lenses, but on the contrary, causing them to be refracted laterallyin all directions at wide angles. Usually, the lens is provided with arefracting or screening surface on one side thereof preferably its innerside, such screening or refracting surface being reticulated in formresembling a fine mesh screen, and comprising ribs 6, 7,. arranged at anangle to each other, which form depressions 8, the ribs 1 being arrangedclose together, so that, the

depressions are minute. Such ribs are preferably rounding, as shown inFigs. 4 and 5, the depressions being rounding as shown in said figures.

Preferably the color is given to the light by the lens which is red,green or amber or any other desired color.

Owing to the screen surfaces on the lenses, greater visibility is givento the signal in which the lamp 2 is illuminated and great contrastgiven between a signal that is illuminated and those that are notilluminated, so that, the observer cannot become confused as to whichsignal is illuminated, as when an ordinary lens or an ordinary coloredsemaphore lens is used. Furthermore the signals have great visibilityeven in strong sunlight, and a great contrast compared with other signallenses reflecting the sunlight, or in which the sunlight can passthrough the lenses and reflect back through it and give a phantomsignal.

Furthermore, in signals in which a lamp 2 is arranged between two lenses4 facing in opposite directions, the sunlight cannot ass through onelens and out through the ot er, and give a phantom signal. In case a colored lamp or a colored glass is used in connection with a white or clearglass lens provided with my screen means, is used, the reflection ofsunlight from the lenses that are not illuminated by lamp is a flatwhite color and hence, there is an even greater contrast between thesignals. In Fig. 7 is shown a plain colored glass 9 between the Whitediffusing lens and the lamp.

Visors 10 are usually employed to shade the lenses from sunlight, andhence, increase the visibility and contrast. Such a visor 10 is hereshown as carried by a ring 11, having circumferentially extending openslots 12 for receiving screws 13. The rings also serve to hold thelenses in position.

As is well known to those skilled in the art, signaling in the daytimeby means of electric lights and lenses has not been satisfactory, onaccount of the low visibility of the signals in sunlight and of the lackof contrast between the signals, that are illuininated and those whicharenot, for the reason that the sunlight reflects strongly from thesignals that are not illuminated by the lamp, and gives the effect tothe observer that the signal is on. My signal is of marked advantage forthe reason that it has great and wide visibility and great contrast inthe brightest sunlight, owing to the wide diffusing feature or screenwhich spreads a wide even flare of light and prevents sun light frombeing reflected from the reflector and also widely spreads sunlight thatdoes strike and is reflected from the lenses so that the visibility of asignal illuminated by sunlight is low, and nil compared with the signallens that is illuminated by the lamp and the reflector.

What I claim is:

1. In a tratlic signal, the combination of a casing, a light source inthe casing, a signal lens in the casing in line with the light sourceand in front of the same, said lens being formed with a reticulatedsurface substantially coextensive therewith and consisting of ribscrossing each other at an angle and forming rounding depressions betweenthe intersections,- said surface resembling a fine mesh screen.

2. In a traffic signal, the combination of a. casing, a light source inthe casing, a signal lens in the casing in line with the light sourceand in front of the same, said lens being formed with a transparentreticulated surface substantially coextensive and consisting of ribscrossing each other at an angle and forming rounding depressions betweenthe intersections, said surface resembling a fine mesh screen and areflector in the rear of the light source.

3. In a trafiic signal, the combination of a casing, a light source inthe casing, a signal lens in the casing in line with the light sourceand in front of the same and a reflector in the rear of the lightsource, said lens being formed with a transparent reticulated surfaceconsisting of ribs crossing each other at an angle and forming roundingde pressions between the intersections, said surface resembling a finemesh screen and a visor for the lens.

In testimony whereof, I have hereunto signed my name, at Syracuse, inthe county of Onondaga, and State of New York, this 15th day ofSeptember, 1924.

FRANK BUCHANAN.

